At an airport, a person is made to walk through the doorway of a metal detector, for security reasons. If she/he is carrying anything made of metal, the metal detector emits a sound. On what principle does this detector work?

At an airport, a perosn is made to walk through the door wy of a metal detector, for security reasons. If she//he is carrying anything made of metal, the metal detector emits a sound. On what principle does this detector work ?

Explain the principle on which the metal detector is used in airport for security reason works.

The parts of electrical objects that need to let electricity pass through are always made of metal, whereas the plastic covering that surrounds wires is an electrical insulator. Give reason.

During extraction of metals, electrolytic refining is used to obtain pure metals. During the process, the impure metal is made the anode and a thin strip of pure metal is made the cathode. The solution of the metal salt is used as an electrolyte. On passing the current through the electrolyte, the pure metal from the anode dissolves from the electrolyte. An equivalent of pure metal from the electrolyte is deposited on the cathode. What is refining of metals?

When light of energy 2.5 eV falls on a metal surface, the maximum K.E. of the emitted electrons is T. If the radiation of energy 4eV is made incident on the same metal surface, the K.E. of the electrons is doubled. What is the work function of the metal ?

Fill in the blanks with the appropriate term from the brackets : One labourer carried four pans of road metal through of 100 metres. If he carries two pans of road metal through a 200 metre distance _____ work will be done.

It was Paheli’s birthday. Her grandmother gave her two gifts made of metals, one old dull silver spoon and a pair of lustrous gold earrings. She was surprised to see the difference in the appearance of the two metals. Can you explain the reason for this difference?